Previously, the communication between a micro-controller and other elements are usually based on an internal integrated circuit (I2C). The internal integrated circuit mainly uses a data transmission line for transmitting a data signal and a clock transmission line for transmitting a clock signal so that each of the bit data contained in the data signal can be identified correctly. However, under the condition of limited area in electronic devices, the communication between different elements by using two transmission lines may not only increase the difficulty of routing between elements, but also increase the number of pins of each element, which produces unnecessary cost and complexity.
To avoid adding unnecessary routing and pins when using the internal integrated circuit, one-wire protocol became a possible solution. Namely, according to the rules set by the one-wire protocol, communications between different elements can be achieved on one single transmission line. However, most of the prior art are used for communication between one master element and one slave element, and only few of the prior art can support the communication between one master element and a plurality of slave elements so the operations are rather inflexible. For example, to communicate with several slave elements, the master element may require several transmission lines each connected to the slave elements respectively. Therefore, the one-wire protocol of the prior art could hardly reduce the complexity of the routing between elements, and could hardly reduce the number of pins of the master element effectively.